Laundry treating apparatus

ABSTRACT

A laundry treating apparatus according to the present disclosure includes a drum having a mounting slot and being configured to receive laundry and rotate about a predetermined rotation axis extending in a front-rear direction, and a lifter disposed on an inner circumferential surface of the drum and extending in the front-rear direction. The lifter includes a lifter frame installed on the inner circumferential surface of the drum, and a frame cover coupled to the lifter frame and protruding radially inward from the inner circumferential surface of the drum. The lifter frame has a catching protrusion protruding from an inner surface of the lifter frame and having a shape that is symmetrical based on a center in a plan view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Korean PatentApplication No. 10-2019-0013925, filed on Feb. 1, 2019, and KoreanPatent Application No. 10-2019-0130784, filed on Oct. 21, 2019, theentire disclosures of which are incorporated herein by reference.

BACKGROUND Technical Field

The present disclosure relates to a laundry treating apparatus having arotary drum in which lifters are provided.

Description of Related Art

Korean Utility Model Registration No. 20-0358903 discloses a washingmachine having a drum in which lifters are provided. A hook protrudesfrom one surface of the lifter, and a hook through-hole is formed in thedrum such that the hook is caught by the hook through-hole.

The hook includes a neck extending from a lifter main body, and a headexpanding from an end of the neck so as to have a larger width than theneck. The lifter is installed such that the head is caught by an outersurface of the drum in a state in which the neck is positioned in thehook through-hole.

However, in order to injection-mold the lifter having the hook asdescribed above, a mold includes an upper mold configured to form anupper surface of the lifter main body, and a lower mold configured toform a lower surface of the lifter main body. However, there is adisadvantage in that undercutting occurs due to a part of the headvertically overlapping the lifter main body.

SUMMARY OF THE INVENTION

An aspect of the present disclosure is to provide a laundry treatingapparatus in which a lifter provided in a drum includes a lifter framecoupled to the drum, and a lifter cover configured to cover the lifterframe, in which the lifter frame may be easily formed by injectionmolding.

Another aspect of the present disclosure is to provide a laundrytreating apparatus in which there is no restriction in terms ofinstallation direction during a process of installing a lifter in adrum, and the lifter may thus be more easily installed in the drum.

Still another aspect of the present disclosure is to provide a laundrytreating apparatus capable of ensuring structural rigidity of a lifterinstalled in a drum and improving an aesthetic appearance of theinterior of the drum by minimizing exposure of an unnecessary portion.

Aspects of the present invention are not limited to those mentionedabove, and other aspects not mentioned above may be clearly understoodby those skilled in the art from the following description.

In a laundry treating apparatus according to an embodiment of thepresent disclosure, a drum into which laundry has been inserted rotatesabout a predetermined rotation axis extending in a front-rear direction,and a lifter provided in the drum lifts up the laundry in the drum whenthe drum rotates.

The lifter includes a lifter frame and a lifter cover. An outer side ofthe lifter frame is covered by the lifter cover.

The lifter frame is made of synthetic resin and includes a frame baseconfigured to adjoin an inner surface of the drum and having an openingportion, an insertion protrusion protruding from a bottom surface of theframe base, and a frame sidewall extending upward from the frame baseand configured to cover at least a part of the opening portion.

A mounting slot is formed in the drum, and the insertion protrusion isinserted into the mounting slot. The insertion protrusion includes avertical portion extending downward from the bottom surface of the framebase, and a catching portion bent toward the inside of the openingportion at a lower end of the vertical portion.

The lifter frame may have a catching protrusion protruding from an innersurface of the lifter frame and having a shape that is symmetrical basedon a center in a plan view.

A planar shape of the frame cover may be formed to cover a regionextending from the region in which any one of the mounting slots in afirst group and the mounting slots in a second group is formed by aspacing distance between the mounting slots in the first group and themounting slots in the second group.

The frame cover may be made of metal. The frame base may have a seatinggroove in which a lower end of the frame cover is seated. The seatinggroove may extend annularly along a circumference of the openingportion, and the catching portion may be disposed in an inner portionsurrounded by the seating groove.

A coupling tab may be formed at the lower end of the frame cover, and atab binding port through which the coupling tab passes may be formed inthe seating groove.

The seating groove extends in the form of a closed curve along acircumference of the lifter frame, and a horizontal projection plane ofthe insertion protrusion may be positioned in the closed curve of theseating groove.

The mounting slot may include an insertion section S1 having a width W1through which the catching portion passes, and a binding section S2extending forward or rearward from the insertion section and having awidth W2 smaller than a width of the catching portion.

The lifter frame may include a frame upper plate disposed at a positionspaced apart from the frame base in a radial direction of the drum andconnected to the frame base through the frame sidewall, and a fasteningboss protruding from a bottom surface of the frame upper plate. The drummay have a fastening hole fastened to the fastening boss by means of apredetermined fastening member.

The pair of lifters may be spaced apart from each other in thefront-rear direction of the drum.

The frame base may include left and right sides that extend in thefront-rear direction and are formed to be parallel to each other. Thetab binding port may be formed in at least one of the left side or theright side, and the coupling tab configured to be inserted into the tabbinding port may be formed at the lower end of the lifter cover.

The insertion protrusions may be formed at the left side and the rightside, respectively. The catching portion of the insertion protrusionformed at the left side may be bent rightward from the vertical portion,and the catching portion of the insertion protrusion formed at the rightside may be bent leftward from the vertical portion.

According to the laundry treating apparatus of the present disclosure,in which the lifter includes the lifter frame coupled to the drum, andthe lifter cover configured to cover the lifter frame, the catchingprotrusion is formed to be symmetrical in a plan view. Accordingly, thecatching protrusion may be installed to come into contact with thecatching tab in any direction, even when the front and rear positions ofthe lifter are changed during the process of installing the lifter inthe drum.

In addition, according to the laundry treating apparatus according tothe present disclosure, the operation of assembling the drum and thelifter may be easily performed without considering the directionality ofthe lifter during the process of installing a plurality of lifters inthe drum.

In addition, according to the laundry treating apparatus according tothe present disclosure, the installation position of the lifter may bechanged depending on the type of drum, an extra mounting slot forchanging the installation position may be covered by the frame cover.

In addition, according to the laundry treating apparatus according tothe present disclosure, the forming position of the insertion protrusionis disposed inward from the forming position of the coupling tab.Accordingly, it is possible to prevent a particular portion from beingstructurally weakened and the insertion protrusion may be covered by theframe cover.

In addition, according to the laundry treating apparatus according tothe present disclosure, the fastening boss is formed on the uppersurface of the lifter frame that has relatively high rigidity.Accordingly, fastening force may be further increased when the fasteningboss and the fastening hole are fastened by means of the fasteningmember.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will become apparent from the detailed description of thefollowing aspects in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a cross-sectional view of a laundry treating apparatusaccording to an exemplary embodiment of the present disclosure;

FIG. 2 is a perspective view of a lifter illustrated in FIG. 1;

FIG. 3 is an exploded perspective view of the lifter illustrated in FIG.2;

FIG. 4 is a plan projection view of the lifter illustrated in FIG. 2;

FIG. 5A is a view illustrating a raw material cut to manufacture alarge-capacity drum, and FIG. 5B is a view illustrating a raw materialcut to manufacture a small-capacity drum;

FIG. 6A is an enlarged view of a part of the drum corresponding to apart A illustrated in FIG. 5A and FIG. 6B is an enlarged view of a partof the drum corresponding to a part B illustrated in FIG. 5A;

FIG. 7A is an enlarged view of a part B of the drum illustrated in FIG.5A and FIG. 7B is an enlarged view of a part C of the drum illustratedin FIG. 5B;

FIG. 8 is a top plan view of a lifter frame, and FIG. 9 is a bottom planview of the lifter frame;

FIG. 10 is a cross-sectional view taken along a line A-A illustrated inFIG. 2;

FIG. 11 is a front view of the lifter frame, and FIG. 12 is a side viewof the lifter frame;

FIG. 13 is a top plan view of a frame cover, FIG. 14 is a front view ofthe frame cover, and FIG. 15 is a side view of the frame cover;

FIGS. 16A and 16B are views illustrating a pair of front and rearlifters illustrated in FIG. 1;

FIG. 17 is a view illustrating the lifters illustrated in FIGS. 16A and16B when viewed from a front side;

FIG. 18A is a view illustrating a state in which the drum illustrated inFIG. 1 is deployed and FIG. 18B is a developed view of the drum havingthe lifters disposed according to another exemplary embodiment of thepresent disclosure;

FIG. 19 is a view (a) illustrating a change in height of a first fabriccaused by the rear lifter in accordance with a rotation angle of thedrum and a view (b) illustrating a change in height of a second fabriccaused by the front lifter that constitutes a set together with the rearlifter;

FIGS. 20A and 20B are views illustrating an inner circumferentialsurface of a drum having mounting slots according to a modified example,FIG. 20A illustrates a small-capacity drum and FIG. 20B illustrates alarge-capacity drum; and

FIG. 21 is a view illustrating another exemplary embodiment of thelifter.

DETAILED DESCRIPTION

Advantages and features of the present disclosure and methods forachieving them will become apparent from the descriptions of aspectsherein below with reference to the accompanying drawings. However, thepresent disclosure is not limited to the aspects disclosed herein butmay be implemented in various different forms. The aspects are providedto make the description of the present disclosure thorough and to fullyconvey the scope of the present disclosure to those skilled in the art.It is to be noted that the scope of the present disclosure is definedonly by the claims.

The shapes, sizes, ratios, angles, the number of elements given in thedrawings are merely exemplary, and thus, the present disclosure is notlimited to the illustrated details. Like reference numerals designatelike elements throughout the specification.

In relation to describing the present disclosure, when the detaileddescription of the relevant known technology is determined tounnecessarily obscure the gist of the present disclosure, the detaileddescription may be omitted.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

The terms “connected” and “coupled” are not restricted to physical ormechanical connections or couplings, and can include electricalconnections or couplings, whether direct or indirect. The connection canbe such that the objects are permanently connected or releasablyconnected. The term “communicatively coupled” is defined as connected,either directly or indirectly through intervening components, and theconnections are not necessarily limited to physical connections, but areconnections that accommodate the transfer of data, fluids, or othermatter between the so-described components.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The term “or” as used herein is to be interpreted as an inclusive ormeaning any one or any combination. Therefore, “A, B or C” means any ofthe following: “A; B; C; A and B; A and C; B and C; A, B and C”. Anexception to this definition will occur only when a combination ofelements, functions, steps or acts are in some way inherently mutuallyexclusive.

Hereinafter, a washing machine will be described as an example of alaundry treating apparatus, but the laundry treating apparatus is notlimited to the washing machine. The laundry treating apparatus is anapparatus for treating laundry (or an object to be dried) such asclothes inputted into a drum 51 and may be a dryer or a washing-dryingmachine.

Referring to FIG. 1, a laundry treating apparatus according to anexemplary embodiment of the present disclosure may include a casing 13configured to define an exterior, a water storage tub 31 disposed in thecasing 13 and configured to store washing water, a washing tub 50rotatably installed in the water storage tub 31 and configured toreceive inserted laundry, and a motor 25 configured to rotate thewashing tub 50. A damper 16 configured to absorb vibration of the waterstorage tub 31 may be provided in the casing 13.

A drum 51 may be rotated about a rotation axis O extending in afront-rear direction, and the drum 51 may constitute the washing tub 50.The rotation axis is approximately horizontal. However, the term“horizontal” does not mean “geometrically horizontal” in a strict sense.In a case in which an inclination is closer to a horizontal axis than avertical axis even though the inclination is formed at a certain anglewith respect to the horizontal axis as illustrated in FIG. 1, it will besaid that the drum 51 or the washing tub 50 is rotated about thehorizontal axis.

A laundry insertion port is formed in a front surface of the casing 13,and a door 21 configured to open or close the laundry insertion port maybe rotatably provided on the casing 13. A tubular gasket 22 is providedsuch that the laundry insertion port and an inlet of the water storagetub 31 communicate with each other. The gasket 22 is made of a softmaterial (for example, rubber). A front end of the gasket 22 may beconnected to a circumference of the laundry insertion port of the casing13, and a rear end of the gasket 22 may be connected to a circumferenceof the inlet of the water storage tub 31.

A water supply valve 33, a water supply pipe 34, and a water supply hose37 may be installed in the casing 13. When the water supply valve 33 isopened and the washing water is supplied, the washing water that haspassed through the water supply pipe 34 may be mixed with detergent in adispenser 35 that stores the detergent, and then the washing water maybe supplied to the water storage tub 31 through the water supply hose37.

An input port of a pump 24 is connected to the water storage tub 31through the drain hose 17, and a discharge port of the pump 24 isconnected to drain pipes 19. The water discharged from the water storagetub 31 through the drain hose 17 is pumped by the pump 24, flows throughthe drain pipes 19, and then is discharged to the outside of the laundrytreating apparatus.

The washing tub 50 may include the drum 51, a front cover 52 coupled toa front end of the drum 51, and a rear cover 53 coupled to a rear end ofthe drum 51. The drum 51 may be formed in the form of a tubular (orcylindrical) body made by rolling up a metal plate (for example, made ofstainless steel) having a plurality of through-holes 51 h (see FIGS. 5Aand 5B) and then joining both ends of the metal plate. The water storedin the water storage tub 31 may be introduced into the washing tub 50through the through-holes 51 h. A plurality of embossed portions 51 a(see FIG. 5A), which are convexly formed by plastic processing, may beformed on an inner circumferential surface of the drum 51, and thethrough-holes 51 h may be formed between the embossed portions 51 a.

An opening portion may be formed in the front cover 52 so that laundrymay be inserted into the drum 51. The inlet of the water storage tub 31communicates with the opening portion. The front cover 52 may be made ofthe same type of material as the drum 51.

The rear cover 53 closes an opened rear side of the drum 51, and aspider 26 connected to a driving shaft 25 a of the motor 25 may becoupled to a rear surface of the rear cover 53. The spider 26 isconfigured to transmit rotational force of the driving shaft 25 a to thewashing tub 50, and the driving shaft 25 a of the motor 25 may becoupled to a center of the spider 26.

A plurality of lifters 61 a, 61 b, 62 a, 62 b, 63 a, and 63 b areprovided in the drum 51. When the drum 51 is rotated, the laundry islifted up by the lifters 61 a, 61 b, 62 a, 62 b, 63 a, and 63 b.

The multiple lifters 61 a, 62 a, and 63 a include first and secondlifters disposed in the front-rear direction of the drum 51.Hereinafter, an example in which the first lifters are front lifters 61a, 62 a, and 63 a and the second lifters are rear lifters 61 b, 62 b,and 63 b spaced rearward apart from the front lifters will be described.However, the first lifter may be the rear lifter and the second liftermay be the front lifter depending on the embodiment.

Referring to FIGS. 1 and 18, the plurality of front lifters 61 a, 62 a,and 63 a, together with the plurality of rear lifters 61 b, 62 b, and 63b, define sets (or pairs), respectively. Three sets of lifters 61 (61 aand 61 b), 62 (62 a and 62 b), and 63 (63 a and 63 b) may be disposed atequal angles about the rotation axis O, but the present disclosure isnot necessarily limited thereto. For example, four sets of lifters maybe disposed at an interval of 90 degrees or five sets of lifters may bedisposed at an interval of 72 degrees about the rotation axis O.

Hereinafter, an example in which the front lifters 61 a, 62 a, and 63 aand the rear lifters 61 b, 62 b, and 63 b have the same structure willbe described, but the present disclosure is not necessarily limitedthereto.

Referring to FIGS. 2 to 4, each of the lifters 61 a, 61 b, 62 a, 62 b,63 a, and 63 b includes a lifter frame 620 fixed to the drum 51, and aframe cover 640 configured to cover the lifter frame 620. The framecover 640 protrudes radially inward (toward the inside of the drum 51)from the inner circumferential surface of the drum 51 and comes intocontact with the laundry. The frame cover 640 is fixed to the drum 51 bymeans of the lifter frame 620 instead of being fixed directly to thedrum 51.

The lifter frame 620 may be made of synthetic resin. The lifter frame620 is preferably formed by injection molding, but the presentdisclosure is not limited thereto.

A lifter made of metal is not only excellent in strength, but alsoluxurious and hygienic. In order to couple the lifter directly to a drummade of metal, it is necessary to weld the lifter to a raw material cutout in a shape of the deployed drum, roll up the raw material in acylindrical shape, and then weld together the ends of the raw materialwhere they meet each other. However, raw material that was flat becomescurved during the process of rolling up the raw material, and as aresult, there is a concern that stress may be applied to the weldedportions between the lifter and the drum and cause the welded portionsto separate.

In order to address this concern, the present disclosure proposes aconfiguration in which a frame cover 640 made of metal is fixed to thedrum 51 by means of a lifter frame 620 made of synthetic resin.

Meanwhile, referring to FIG. 3 and FIGS. 8 to 12, the whole of an outersurface 620 a (see FIG. 8) of the lifter frame 620 has a convex shape,and an inner surface 620 b (see FIG. 9) of the lifter frame 620 has aconcave shape. Specifically, the lifter frame 620 may include a framebase 621, a frame upper plate 623, and a frame sidewall 622.

The frame base 621 is fixed to the inner circumferential surface of thedrum 51. The frame base 621 may have a ring shape (or a closed shapeformed by a single line) opened at a central portion thereof.

The frame upper plate 623 is spaced apart from the frame base 621 in thedirection toward the inside of the drum 51 and connected to the framebase 621 by means of the frame sidewall 622. The frame sidewall 622 maybe formed in the form of a tubular (or cylindrical) body, such that alower end of the frame sidewall 622 is connected to the frame base 621,and an upper end of the frame sidewall 622 is connected to the frameupper plate 623.

The frame sidewall 622 is shaped such that a contour of a cross sectionthereof gradually decreases upward from the lower end connected to theframe base 621 (or in the radial direction of the drum 51) (or graduallydecreases in a direction away from the inner circumferential surface ofthe drum 51), and the contour of the cross section is smallest at aportion that meets the frame upper plate 623.

One or more water flow inlet holes may be formed in the drum 51 so as toallow the washing water stored in the water storage tub 31 to beintroduced to the inside of the frame cover 640. Any opening portionformed in a region covered by the frame cover 640 may be a water flowinlet hole. For example, some of the through-holes 51 h, which arepositioned inside the frame cover 640, may be water flow inlet holes.Furthermore, mounting slots 511 a and 511 b, fastening holes 513 a and513 b, and opening portions 512 a and 512 b, which will be describedbelow, may be water flow inlet holes.

One or more water flow through-holes 624 and 624 a may be formed in thelifter frame 620. Any opening may be a water flow through-hole 624 aslong as the opening is formed in the lifter frame 620 and allows theinside and the outside of the lifter frame 620 to communicate with eachother.

The water flow through-hole 624 may be formed in the frame sidewall 622and/or the frame upper plate 623. The washing water stored in theconcave space of the lifter frame 620 may be discharged through thewater flow through-hole 624.

One or more water flow discharge holes 646 h may be formed in the framecover 640 to discharge the washing water in the lifters 61 a, 61 b, 62a, 62 b, 63 a, and 63 b into the drum 51. The washing water in theconcave space inside the lifter frame 620 may pass through the waterflow through-hole 624, and then may be discharged into the drum 51through the water flow discharge hole 646 h.

An outer surface 640 a of the frame cover 640, which is exposed to theinside of the drum 51 and comes into contact with the laundry, has aconvex shape, and an inner surface of the frame cover 640 has a concaveshape that corresponds to the convex outer surface 620 a of the lifterframe 620. The frame cover 640 may be made of metal, preferablystainless steel, but the present disclosure is not limited thereto. Theframe cover 640 may be formed by plastically processing (for example,pressing) a metal plate having a predetermined thickness.

The frame cover 640 may include a cover sidewall 645 extending upwardfrom a lower end adjoining the frame base 621, and a cover upper plate646 configured to cover an upper side of the cover sidewall 645. Thecover upper plate 646 is approximately parallel to the frame upper plate623. The plurality of water flow discharge holes 646 h may be formed inthe cover upper plate 646.

The cover sidewall 645 is shaped such that a contour of a cross sectionthereof gradually decreases upward from the lower end (or in the radialdirection of the drum 51) (or gradually decreases in the direction awayfrom the inner circumferential surface of the drum 51), and the contourof the cross section is smallest at a portion that meets the cover upperplate 646.

The lifter frame 620 includes spacers 625 that protrude from the frameupper plate 623 and allow the frame cover 640 to be spaced apart fromthe frame upper plate 623. The spacer 625 protrudes from the frame upperplate 623 to the inner surface of the frame cover 640.

The inner surface of the frame cover 640 may be spaced apart from theframe upper plate 623 to a degree equal to or greater than a length (orheight) of the spacer 625 protruding from the frame upper plate 623. Thespacer 625 may be spaced apart from the inner surface of the frame cover640 at a predetermined distance. In this case, the inner surface of theframe cover 640 is spaced apart from the frame upper plate 623 at adistance equal to a sum of the height of the spacer 625 and the intervalbetween the spacer 625 and the inner surface of the frame cover 640.When the frame cover 640 is pressed by external force, the frame cover640 comes into contact with the frame upper plate 623, such that theframe cover 640 is prevented from being deformed any further.

Alternatively, the spacer 625 may be configured to come into contactwith the frame cover 640, depending on the embodiment. In this case, thespacer 625 protrudes from the outer surface 620 a of the lifter frame620 and adjoins the inner surface of the frame cover 640. Because thespacer 625 supports the inner surface of the frame cover 640 in thestate in which the frame upper plate 623 is spaced apart from the framecover 640, the state in which the frame cover 640 is spaced apart fromthe frame upper plate 623 may be maintained even though the frame cover640 is pressed toward the lifter frame 620 by external force.

The spacer 625 may have a cross-shaped rib structure. Specifically, thespacer 625 may include a vertical rib 625 a extending on the frame upperplate 623 in a longitudinal direction of the lifter frame 620 (or thefront-rear direction), and a horizontal rib 625 b extending whilecrossing the vertical rib 625 a. The vertical rib 625 a and thehorizontal rib 625 b may be orthogonal to each other.

Referring to FIG. 10, the inner surface of the cover upper plate 646 maybe spaced apart from the outer surface of the frame upper plate 623.That is, a predetermined separation space (or a gap g1) may be formedbetween the inner surface of the cover upper plate 646 and the outersurface of the frame upper plate 623, and the separation space g1 mayserve as a flow path that guides the washing water to the water flowdischarge hole 646 h.

A separation space g2 may also be formed between the frame sidewall 622and the cover sidewall 645. A seating groove 621 r (see FIGS. 8 and 9)to be described below is formed in the frame base 621 and disposed at aposition toward the outside of the frame base 621 spaced apart from theframe sidewall 622 at a predetermined distance. Therefore, the lower endof the cover sidewall 645 positioned in the seating groove 621 r isspaced apart from the frame sidewall 622. Because the lower end of theframe cover 640 is spaced apart from the frame sidewall 622 by theseating groove 621 r and the cover upper plate 646 is spaced apart fromthe frame upper plate 623 by the spacer 625, two points of the framecover 640, which are the lower end of the frame cover 640 and theportion of the frame cover 640 supported by the spacer 625, are forciblyspaced apart from the lifter frame 620, and as a result, the state inwhich the cover sidewall 645 positioned between the two points is spacedapart from the lifter frame 620 is maintained.

The washing water introduced into each of the lifters 61 a, 61 b, 62 a,62 b, 63 a, and 63 b is introduced into the separation spaces g1 and g2,and water flows formed in the separation spaces g1 and g2 during therotation of the washing tub 50 clean the outer surface of the lifterframe 620 and the inner surface of the frame cover 640. Foreignsubstances produced during the cleaning process may be dischargedthrough the water flow discharge hole 646 h formed in the frame cover640 or through the water flow inlet hole formed in the drum 51. The flowpaths are formed between the lifter frame 620 and the frame cover 640 bythe separation spaces g1 and g2, and as a result, this configuration maybe advantageous in maintaining the lifters 61 a, 62 a, 63 a, 61 b, 62 b,and 63 b in a clean state.

The frame cover 640 may have domes 641, 642, 643, and 644 formed at thepositions corresponding to the spacers 625. That is, the spacers 625 maybe disposed below the domes 641, 642, 643, and 644. In the case in whichthe plurality of spacers 625 are formed in the exemplary embodiment, theplurality of domes 641, 642, 643, and 644 may be formed at the positionscorresponding to the plurality of spacers 625, respectively.

The domes 641, 642, 643, and 644 may be formed on the cover upper plate646. An inner surface of each of the domes 641, 642, 643, and 644, whichfaces the spacer 625, may be concavely formed, and an outer surface ofeach of the domes 641, 642, 643, and 644 may be convexly formed. Theconcave inner surface of each of the domes 641, 642, 643, and 644 maycome into contact with the spacer 625.

The domes 641, 642, 643, and 644 are convexly formed by pressing thecover upper plate 646, which is made of metal. The plurality of domes641, 642, 643, and 644 may be disposed in the longitudinal direction ofthe cover upper plate 646 (or the longitudinal direction of the lifters61 a, 61 b, 62 a, 62 b, 63 a, and 63 b). The one or more water flowdischarge holes 646 h may be formed between the adjacent domes 641, 642,643, and 644.

The domes 641, 642, 643, and 644 may include two or more domes of whichthe depth of the concave portion of the inner surfaces thereof isdifferent from each other. In more detail, the domes 641, 642, 643, and644 may include large domes 641 and 644, each of which have a concaveportion of a first depth, and small domes 642 and 643, each of whichhave a concave portion of a second depth smaller than the first depth.The height of the spacers 625 a and 625 d corresponding to the largedomes 641 and 644 may be greater than the height of the spacers 625 band 625 c corresponding to the small domes 642 and 643.

The domes 641, 642, 643, and 644 may include the two or more domeshaving different sizes. Each of the domes 641, 642, 643, and 644 mayhave a circular shape, but the present disclosure is not necessarilylimited thereto. Here, the ‘size’ may be determined based on the shapewhen the concave portion of the inner surface of each of the domes 641,642, 643, and 644 are viewed from above, and for example, the ‘size’ maybe defined as a diameter of the concave portion. However, since thedifference between the inner diameter and the outer diameter of each ofthe domes 641, 642, 643, and 644 is merely due to the thickness of thematerial, the size may be defined based on the outer diameter of each ofthe domes 641, 642, 643, and 644.

The size of the spacer 625 may also vary depending on the size of eachof the domes 641, 642, 643, and 644. That is, in the case in which thereare the large domes 641 and 644 and the small domes 642 and 643 asillustrated in FIG. 13, the spacer 625 corresponding to the large domes641 and 644 may be larger than the spacer 625 corresponding to the smalldomes 642 and 643.

The two small domes 643 and 644 may be positioned between the pair oflarge domes 641 and 642, and the water flow discharge holes 646 h may beformed between the domes 641, 642, 643, and 644. The plurality of waterflow discharge holes 646 h may be arranged in a direction crossing thelifters 61 a, 61 b, 62 a, 62 b, 63 a, and 63 b (or a directionorthogonal to the length of each of the lifters 61 a, 61 b, 62 a, 62 b,63 a, and 63 b).

The water stored in the water storage tub 31 is introduced into thelifters 61 a, 61 b, 62 a, 62 b, 63 a, and 63 b through the openingportion. The lifter frame 620 is a structure having one or more of thewater flow through-holes 624, and the water introduced into the lifters61 a, 61 b, 62 a, 62 b, 63 a, and 63 b may reach the water flowdischarge holes 646 h through the water flow through-holes 624.

The washing water introduced into the lifters 61 a, 61 b, 62 a, 62 b, 63a, and 63 b is raised by the rotation of the washing tub 50 in the statein which the washing water is in the lifters 61 a, 61 b, 62 a, 62 b, 63a, and 63 b, and the washing water is discharged (or sprayed) throughthe water flow discharge holes 646 h in this process.

Referring to FIGS. 2, 3, 10, and 13 to 15, the frame cover 640 mayinclude one or more washing protrusions 603 and 604 having a ring shapeor one or more washing rings protruding from the outer surface of thecover sidewall 645. The plurality of washing protrusions 603 and 604 maybe disposed in parallel with one another. In the exemplary embodiment,two washing protrusions 603 and 604 are provided, but the presentdisclosure is not necessarily limited thereto. In the case in which theframe cover 640 is made of metal, the washing protrusions 603 and 604may be formed by pressing.

Each of the washing protrusions 603 and 604 has a shape corresponding(or similar) to the contour of the cover sidewall 645, and preferably,the washing protrusion may protrude to a predetermined height from thecover sidewall 645. Since the contour of the cover sidewall 645decreases upward, among the washing protrusions 603 and 604, the washingprotrusion that is positioned at an upper side is smaller than the otherwashing protrusion.

A frictional force applied between the laundry and the washingprotrusions 603 and 604 generates an effect of rubbing the laundry,thereby improving washing power. In addition, because the washingprotrusions 603 and 604 assist in the operation of lifting up thelaundry, physical force (for example, force for lifting up or strikingthe laundry) of a level as in the related art may be applied to thelaundry even when the height of each of the lifters 61 a, 61 b, 62 a, 62b, 63 a, and 63 b is decreased to be smaller than that in the relatedart.

The frame cover 640 may be coupled to the lifter frame 620. Referring toFIGS. 2 and 3, one or more coupling tabs 648 may be formed at the lowerend of the frame cover 640. As illustrated in FIG. 14, the coupling tabs648 may be formed at a left side 645L or a right side 645R at the lowerend when the frame cover 640 is viewed from the front side. The leftside 645L and the right side 645R may be straight sections extending inthe front-rear direction.

Referring to FIGS. 8 and 9, tab binding ports 621 h, through which thecoupling tabs 648 pass from above, may be formed in the lifter frame620. The tab binding ports 621 h may be formed at positionscorresponding to the coupling tabs 648, respectively. A coupling tab 648passes through the tab binding port 621 h, and the passing portion ofthe coupling tab 648 is bent and caught by a rim of the tab binding port621 h (or a bottom surface of the frame base 621), such that the lifterframe 620 and the frame cover 640 may be coupled to each other.

Meanwhile, the seating groove 621 r, which corresponds to the lower endof the frame cover 640, may be formed in the frame base 621 of thelifter frame 620. The lower end of the frame cover 640 may be insertedand seated in the seating groove 621 r. In this case, the tab bindingport 621 h may be formed in the seating groove 621 r.

Hereinafter, a structure in which the lifter frame 620 and the drum 51are coupled to each other will be described.

Referring to FIGS. 8, 9, 11, and 12, one or more insertion protrusions627 may be formed on each of the front lifters 61 a, 62 a, and 63 aand/or the rear lifters 61 b, 62 b, and 63 b. Further, referring toFIGS. 5A to 7B, the drum 51 may have mounting slots 511 a 1 in a firstgroup G1 and mounting slots 511 a 2 in a second group G2. Each of thegroups G1 and G2 may include the one or more mounting slots 511 a 1(1)to 511 a 1(4). Here, the ‘group’ is a set of mounting slots and mayinclude one or a plurality of mounting slots.

The mounting slots 511 a 1 in the first group G1 and the mounting slots511 a 2 in the second group G2 may include a number of the mountingslots 511 a 1(1) to 511 a 1(4) and 511 a 2(1) to 511 a 2(4) thatcorresponds to the number of the one or more insertion protrusions 627.That is, in the case in which the mounting slots in the first group G1and the second group G2 are used to install the front lifters 61 a, 62a, and 63 a, the number of mounting slots 511 a 1 in the first group G1and the number of mounting slots 511 a 2 in the second group G2 maycorrespond to the number of insertion protrusions 627 provided on eachof the front lifters 61 a, 62 a, and 63 a.

Likewise, depending on the embodiment, in the case in which the mountingslots in the first group G1 and the second group G2 are used to installthe rear lifters 61 b, 62 b, and 63 b, the number of mounting slots 511a 1 in the first group G1 and the number of mounting slots 511 a 2 inthe second group G2 may correspond to the number of insertionprotrusions 627 provided on each of the rear lifters 61 b, 62 b, and 63b.

The one or more insertion protrusions 627 formed on each of the frontlifters 61 a, 62 a, and 63 a or the rear lifters 61 b, 62 b, and 63 bmay be selectively fastened to the mounting slots 511 a 2 in the firstgroup G1 or the second group G2. The position at which the lifter isinstalled may be determined depending on whether the one or moreinsertion protrusions 627 formed on each of the lifters 61 a, 62 a, 63a, 61 b, 62 b, and 63 b are inserted into the mounting slots thatconstitute any one of the first group G1 or the second group G2.

Hereinafter, the example in which the mounting slots 511 a, whichconstitute the first group G1 and the second group G2, are used toinstall the front lifters 61 a, 62 a, and 63 a will be described, butthe mounting slots may be formed in the same manner in order to installthe rear lifters 61 b, 62 b, and 63 b.

The mounting slots 511 a 2 in the second group G2 are formed in a regionshifted rearward within a range in which the mounting slots 511 a 2 inthe second group G2 overlap the mounting slots 511 a 1 in the firstgroup G1. For reference, in FIG. 6B, a first region M1 indicates aregion in which the mounting slots 511 a 1 in the first group G1 areformed, and a second region M2 indicates a region in which the mountingslots 511 a 2 in the second group G2 are formed. Hereinafter, asillustrated in FIG. 6B, the mounting slots 511 a 2 in the second groupG2 are disposed rearward from the mounting slots 511 a 1 in the firstgroup G1.

Referring to FIGS. 5A to 7B, the mounting slots 511 a 2 in the secondgroup G2 are spaced apart from the mounting slots 511 a 1 in the firstgroup G1 in the rearward direction at a predetermined distance D.Therefore, when the insertion protrusions 627 are installed in themounting slots 511 a 1 in the first group G1, each of the front lifters61 a, 62 a, and 63 a is positioned further forward by a distance D incomparison with a case in which the insertion protrusions 627 areinstalled in the mounting slots 511 a 2 in the second group G2. Asillustrated in FIGS. 5A and 5B, the metal plate of the large-capacitydrum 51 further extends forward by a distance E in comparison with acase in which the drum is the small-capacity drum. In the case of thelarge-capacity drum (FIG. 5A), the front lifters 61 a, 62 a, and 63 aare installed by using the mounting slots 511 a 1 in the first group G1,such that the front lifters 61 a, 62 a, and 63 a may be installedrelatively further forward in comparison with the case in which the drumis the small-capacity drum (FIG. 5B). Therefore, the laundry positionedin the region corresponding to the distance E may easily come intocontact with the front lifters 61 a, 62 a, and 63 a while the drum 51rotates.

The mounting slots 511 a in the respective groups G1 and G2 may bedisposed in rows in the front-rear direction. Particularly, the mountingslots 511 a in each of the groups G1 and G2 are disposed in two rows.Further, when the entire configuration is viewed without distinguishingthe groups, the mounting slots 511 a may be arranged along commonreference lines extending in the front-rear direction. Preferably, inthe embodiment, the mounting slots are disposed on two straight linesparallel to each other.

In more detail, the mounting slots 511 a 1 in the first group G1 mayinclude two or more first mounting slots 511 a 1(1) and 511 a 1(2)arranged at a first interval T in a first row P1 extending in thefront-rear direction. Furthermore, the mounting slots 511 a 1 in thefirst group G1 may further include two or more first mounting slots 511a 1(3) and 511 a 1(4) arranged at the first interval T in a second rowP2 parallel to the first row P1.

The mounting slots 511 a 2 in the second group G2 may include two ormore second mounting slots 511 a 2(1) and 511 a 2(2) arranged in thefirst row P1 at positions shifted, by a second interval D smaller thanthe first interval T, rearward from the mounting slots 511 a 1 in thefirst group G1.

Furthermore, the mounting slots 511 a 2 in the second group G2 mayfurther include two or more second mounting slots 511 a 2(3) and 511 a2(4) arranged in the second row P2 at positions shifted, by the intervalT, rearward from the mounting slots 511 a 1 in the first group G1.

Hereinafter, the mounting slots 511 a 1 and 511 a 2, which can be usedto install the front lifters 61 a, 62 a, and 63 a, are defined as beingin a front lifter installation group, and the mounting slots 511 b (seeFIG. 6A), which can be used to install the rear lifters 61 b, 62 b, and63 b, are defined as being in a rear lifter installation group.

The plurality of front or rear lifters 61 a, 62 a, 63 a, 61 b, 62 b, and63 b may be disposed in a circumferential direction of the drum 51, suchthat the plurality of front lifter installation groups may be disposedin the circumferential direction, and likewise, the plurality of rearlifter installation groups may also be disposed in the circumferentialdirection.

Hereinafter, the mounting slot belonging to the front lifterinstallation group is referred to as the front mounting slot 511 a, andthe mounting slot belonging to the rear lifter installation group isreferred to as the rear mounting slot 511 b.

Referring to FIGS. 8 to 12, the insertion protrusion 627 may protrudefrom the frame base 621. The insertion protrusion 627 may include avertical portion 627 a (see FIG. 11) protruding downward from the bottomsurface of the frame base 621, and a catching portion 627 b bent in thehorizontal direction from the vertical portion 627 a. The catchingportion 627 b may protrude toward the inside of the ring-shaped framebase 621 when viewed from above.

As illustrated in FIG. 11, the insertion protrusions 627 may be formedat left and right sides of the frame base 621, respectively, when thelifter frame 620 is viewed from the front side. Two or more insertionprotrusions 627 may be formed along one side of the frame base 621 (orin the front-rear direction).

Specifically, the insertion protrusion 627(L) formed at the left side ofthe frame base 621 may include the catching portion 627 b which is bentrightward. On the contrary, the insertion protrusion 627(R) formed atthe right side of the frame base 621 may include the catching portion627 b which is bent leftward.

Referring to FIGS. 6A and 6B, each of the mounting slots 511 a and 511 bmay be shaped to have a length L1 in the approximately front-reardirection of the drum 51. Each of the mounting slots 511 and 511 b mayinclude an insertion section S1 having a predetermined width W1, and abinding section S2 extending rearward or forward from the insertionsection S1 and having a smaller width (W2<W1) than the insertion sectionS1. In the exemplary embodiment, the binding section S2 extends rearwardfrom a rear end of the insertion section S1, but the present disclosureis not necessarily limited thereto. On the contrary, the binding sectionS2 may extend forward from a front end of the insertion section S1.

Furthermore, as illustrated in FIGS. 20A and 20B, to be described below,in the exemplary embodiment, the binding section S2 of the frontmounting slot 511 a may extend forward from the front end of theinsertion section 51, and the binding section S2 of the rear mountingslot 511 b may extend rearward from the rear end of the insertionsection S1.

Meanwhile, referring to FIGS. 5A to 7B, when installing the lifter frame620 in the drum 51, the insertion protrusion 627 of the lifter frame 620passes through the insertion section S1, and the lifter frame 620 ispushed rearward, such that the vertical portion 627 a is moved forwardalong the binding section S2, and thus the catching portion 627 b ispositioned below the binding section S2. In this case, since the bottomsurface of the frame base 621 is in close contact with the innercircumferential surface of the drum 51, and a width W3 (see FIG. 11) ofthe catching portion 627 b is larger than the width W2 of the bindingsection S2, the catching portion 627 b cannot pass through the bindingsection S2 from the lower side to the upper side.

Meanwhile, the seating groove 621 r may extend in the form of a closedcurve along a circumference of the lifter frame 620, and a horizontalprojection plane of the insertion protrusion 627 may be positioned inthe closed curve of the seating groove 621 r.

That is, the insertion protrusion 627 may be positioned inward from theseating groove 621 r. In the case in which the coupling tab 648 and thetab binding port 621 h are formed on the seating groove 621 r, theforming position of the insertion protrusion 627 and the formingpositions of the coupling tab 648 and the tab binding port 621 h may notoverlap each other.

As described above, since the forming position of the insertionprotrusion 627 is disposed inward from the forming positions of thecoupling tab 648 and the tab binding port 621 h, it is possible toprevent a particular portion from being structurally weakened, and theinsertion protrusion 627 may be covered by the frame cover 640.

Therefore, it is possible to ensure structural rigidity of the lifters61 a, 61 b, 62 a, 62 b, 63 a, and 63 b installed in the drum 51, andimprove an aesthetic appearance of the interior of the drum 51 byminimizing exposure of an unnecessary portion.

Meanwhile, referring to FIGS. 8 to 11, the frame sidewall 622 mayinclude a sidewall left portion 622L having a lower end connected to aleft side 621 a of the frame base 621, and a sidewall right portion 622Rhaving a lower end connected to a right side 621 b of the frame base621. At least one of the sidewall left portion 622L or the sidewallright portion 622R may define an acute angle with respect to the framebase 621. Particularly, at least one of the sidewall left portion 622Lor the sidewall right portion 622R may be symmetric with each other whenviewed from the front side.

The frame sidewall 622 may have a mold ejection port 624 a formed at aposition corresponding to the insertion protrusion 627 when the lifterframe 620 is viewed vertically downward from above. The mold ejectionport 624 a may be formed in at least one of the sidewall left portion622L or the sidewall right portion 622R.

The lifter frame 620 may be formed by injection molding. In this case,the mold may include an upper mold that forms the upper surface of thelifter frame 620, and a lower mold that forms the lower surface of thelifter frame 620.

The upper surface of the insertion protrusion 627 may be formed by theupper mold. Since the insertion protrusion 627 is positioned at thelower side of the frame sidewall 622, an opening portion, through whicha portion of the upper mold defining the upper surface of the insertionprotrusion 627 may pass during the process of opening the mold, needs tobe formed in a region that overlaps the insertion protrusion 627 in adirection in which the upper mold is opened on the frame sidewall 622(or a vertically upward direction from the frame base 621) so that amold portion of the upper mold, which forms the upper surface of theinsertion protrusion 627 (particularly, the upper surface of thecatching portion 627 b), may be moved upward (or so that the upper moldmay be withdrawn without undercutting during the process of opening themold), and the mold ejection port 624 a is the opening portion. Forreference, PL in FIG. 11 indicates a parting line formed by the uppermold and the lower mold.

As illustrated in FIG. 8, when the lifter frame 620 is viewed verticallydownward from above (hereinafter, referred to as ‘a plan view of thelifter frame’), the catching portion 627 b of the insertion protrusion627 is positioned in the mold ejection port 624 a (or overlaps the moldejection port 624 a). Further, in the plan view of the lifter frame, anouter periphery of the catching portion 627 b is spaced apart from a rimof the mold ejection port 624 a, excluding the portion 627 a connectedto the vertical portion 627 a.

Referring to FIGS. 9 and 10, a catching protrusion 626 may be formed onat least one of the front lifters 61 a, 62 a, and 63 a or the rearlifters 61 b, 62 b, and 63 b. The catching protrusion 626 may protrudedownward from the concave inner surface 620 b of the lifter frame 620.

Referring to FIGS. 6A and 6B, the opening portions 512 a and 512 b, intowhich the catching protrusions 626 are inserted, may be formed in thedrum 51. The pair of opening portions 512 a 1 and 512 a 2 for installingthe front lifters 61 a, 62 a, and 63 a may be spaced apart from oneanother by an interval D in the front-rear direction.

The catching protrusion 626 is selectively inserted into any one of thepair of opening portions 512 a 1 and 512 a 2 depending on whether theinsertion protrusions 627 are inserted into the mounting slots 511 a 1in the first group G1 or the mounting slot 511 a 2 in the second groupG2.

Catching tabs 514 a and 514 b, which each come into contact with (or arecaught by) the lower end of the catching protrusion 626, may be formedon rims of the opening portions 512 a and 512 b. The catching tabs 514 aand 514 b may come into contact with the lateral surfaces of thecatching protrusions 626 in the opening portions 512 a and 512 b,thereby restricting lateral movement of the catching protrusions 626.

Meanwhile, the positions of the catching tabs 514 a and 514 b may bedetermined based on the relative positions of the mounting slots 511 aand 511 b with respect to the insertion section 51 of the bindingsection S2. That is, as illustrated in FIGS. 6A and 6B, when the bindingsection S2 is positioned rearward from the insertion section 51, thecatching tabs 514 a and 514 b are positioned in a first concave portion626 a at the front side of the catching protrusions 626. The catchingtabs 514 a and 514 b may extend rearward from the front end of theopening portion 512 to restrict the movement of the catching protrusions626 when the catching protrusion 626 is about to move forward (that is,the insertion protrusion 627 is about to move from the binding sectionS2 to the insertion section 51).

On the contrary, like the mounting slot 511 a illustrated in FIGS. 20Aand 20B, when the binding section S2 is positioned forward from theinsertion section 51, the catching tabs 514 a and 514 b are positionedin a second concave portion 626 b at the rear side of the catchingprotrusions 626. The catching tabs 514 a and 514 b may extend forwardfrom the rear end of the opening portion 512 to restrict the movementsof the catching protrusions 626 when the catching protrusion 626 isabout to move rearward (that is, the insertion protrusion 627 is aboutto move from the binding section S2 to the insertion section 51).

The catching tabs 514 a and 514 b may be bent at a predetermined angleto the outside of the drum 51 based on the portion connected to the rimsof the opening portions 512 a and 512 b.

The lateral surfaces of the catching protrusions 626 may come intocontact with the catching tabs 514 a and 514 b even in the state inwhich the lower ends of the catching protrusions 626 are not insertedinto the opening portions 512 a and 512 b. When the lifter frame 620 isabout to move (that is, about to move in a direction opposite to adirection in which the lifter frame 620 is installed) such that thevertical portion 627 a moves from the binding section S2 to theinsertion section 51, the movement is restricted as the catching tabs514 a and 514 b interfere with the lower ends of the catchingprotrusions 626.

Referring to FIG. 9, at the lower end of the catching protrusion 626,the first concave portion 626 a may be formed at a side facing thecatching tabs 514 a and 514 b. In the state in which the lifter frame620 has been completely installed, the catching tabs 514 a and 514 b maybe positioned in the first concave portion 626 a.

At the lower end of the catching protrusion 626, the second concaveportion 626 b may be further formed at a side opposite to the firstconcave portion 626 a. When the lifter frame 620 is installed in a statein which the front and rear sides of the lifter frame 620 are changed,the catching tabs 514 a and 514 b may be positioned in the secondconcave portion 626 b.

In this case, the catching protrusion 626 may be formed to besymmetrical based on the center in a plan view of the lifter frame 620.That is, as illustrated in FIG. 9, the catching protrusion 626 may beformed to be symmetrical about the vertical and horizontal axes based onthe center thereof.

In particular, the first concave portion 626 a and the second concaveportion 626 b of the catching protrusion 626 may be formed to besymmetrical in both directions based on the longitudinal direction ofthe lifter frame 620.

Therefore, the catching protrusion 626 may be installed to come intocontact with the catching tabs 514 a and 514 b in any direction, evenwhen the front and rear positions of the lifters 61 a, 61 b, 62 a, 62 b,63 a, and 63 b are changed during the process of installing the lifters61 a, 61 b, 62 a, 62 b, 63 a, and 63 b in the drum 51.

Therefore, the installation operator may easily install the lifters 61a, 61 b, 62 a, 62 b, 63 a, and 63 b in the drum 51 without consideringthe directions in which the lifters 61 a, 61 b, 62 a, 62 b, 63 a, and 63b are installed.

Meanwhile, referring to FIG. 9, fastening bosses 628 may be formed on atleast one of the front lifters 61 a, 62 a, and 63 a or the rear lifters61 b, 62 b, and 63 b. The fastening boss 628 may protrude downward fromthe inner surface 620 b of the lifter frame 620. The fastening boss 628may extend from the frame upper plate 623. Two or more fastening bosses628 may be provided to be spaced apart from one another in thefront-rear direction.

Referring to FIGS. 5A to 6B, fastening holes 513 a and 513 b may beformed in the drum 51. The fastening holes 513 a and 513 b may include afirst fastening hole 513 a 1 formed at a position corresponding to thefastening boss 528 when the insertion protrusion 627 of the lifter frame620 is installed in the mounting slot 511 a 1 in the first group G1, anda first fastening hole 513 a 2 formed at a position corresponding to thefastening boss 528 when the insertion protrusion 627 of the lifter frame620 is installed in the mounting slot 511 a 2 in the second group G2.The pair of first fastening holes 513 a 1(1) and 513 a 1(2) are providedto correspond to the pair of fastening bosses 528, and the secondfastening holes 513 a 2 including a pair of second fastening holes 513 a2(1) and 513 a 2(2) may be provided.

Referring to FIGS. 7A and 7B, the fastening boss 628 may be selectivelyfastened to the first fastening hole 513 a 1 or the second fasteninghole 513 a 2 by means of a predetermined fastening member (hereinafter,for exemplary purposes, a screw 98) based on whether the insertionprotrusion 627 is inserted into the mounting slot 511 a 1 in the firstgroup G1 or the mounting slot 511 a 2 in the second group G2.

In the state in which the insertion protrusion 627 is inserted into themounting slot 511 a and the lifter frame 620 is temporarily assembled,the screw 98 passes through the fastening hole 513 a from the outside ofthe drum 51 and is then fastened to the fastening boss 628, such thatthe lifter frame 620 may be completely installed.

In this case, the fastening boss 628 may protrude from the inner surfaceof the frame upper plate 623 in the direction toward the innercircumferential surface of the drum 51.

In the structure of the lifter frame 620, the frame upper plate 623 hasrelatively higher rigidity than the frame sidewall 622 having theplurality of holes.

Therefore, in order to more rigidly install the lifters 61 a, 61 b, 62a, 62 b, 63 a, and 63 b in the drum 51, the fastening boss 628 to befastened, by means of the fastening member, to the fastening hole 513 aof the drum 51 may be formed on the frame upper plate 623.

As described above, since the fastening boss 628 is formed on the uppersurface of the lifter frame 620 that has relatively high rigidity,fastening force may be further increased when the fastening boss 628 isfastened to the fastening hole 513 a by means of the fastening member.

Meanwhile, as described above, as illustrated in FIG. 7A or 7B, theinstallation position of the lifter frame 620 may vary depending onwhether the insertion protrusion 627 is inserted into the mounting slot511 a 1 or the mounting slot 511 a 2. In any case, the mounting slots511 a 1 and 511 a 2, the opening portions 512 a 1 and 512 a 2, and thefastening holes 513 a 1 and 513 a 2 are hidden by the frame cover 640 inthe state in which the lifter is completely installed. That is, themounting slots 511 a 1 and 511 a 2, the opening portions 512 a 1 and 512a 2, and the fastening holes 513 a 1 and 513 a 2 are positioned insidethe frame cover 640, and thus are not exposed to the inside of the drum51.

In other words, in the state in which the at least one insertionprotrusion 627 provided on each of the lifters 61 a, 62 a, 63 a, 61 b,62 b, and 63 b is fastened to the mounting slot (for example, 511 a 1)in any one group (for example, G1) among the mounting slots 511 a in thefirst group G1 and the second group G2, the mounting slot (for example,511 a 2) in the other group (for example, G2) may be hidden inside thedrum 51 by the lifter.

In more detail, in the state in which the at least one insertionprotrusion 627 provided on each of the front lifters 61 a, 62 a, and 63a is inserted into the mounting slot in any one group (for example, G1)of the first group G1 and the second group G2, the front end of each ofthe front lifters 61 a, 62 a, and 63 a may be positioned forward fromthe mounting slots 511 a 1(1) to 511 a 1(4) and 511 a 2(1) to 511 a 2(4)belonging to the first group G1 and the second group G2.

In addition, the rear end of each of the front lifters 61 a, 62 a, and63 a may be positioned rearward from any of the mounting slots 511 a1(1) to 511 a 1(4) and 511 a 2(1) to 511 a 2(4) belonging to the firstgroup G1 and the second group G2.

Since all of the mounting slots 511 a 1(1) to 511 a 1(4) and 511 a 2(1)to 511 a 2(4) used to install the front lifters 61 a, 62 a, and 63 a arepositioned between the front ends and the rear ends of the front lifters61 a, 62 a, and 63 a, the mounting slots may be hidden by being coveredby the front lifters 61 a, 62 a, and 63 a.

Manufacturers of laundry treating apparatuses sometimes produce varioustypes of products having drums having different capacities. In thiscase, a metal plate having the mounting slots 511 a and 511 b, theopening portions 512 a and 512 b, the fastening holes 513 a and 513 b,and the like is cut out based on a predetermined standard, the rawmaterial 51′ or 51″ (see FIGS. 5A and 5B) cut out in this manner isrolled up, and the ends of the raw material are joined together so as tomanufacture the drum 51. In this case, the metal plate is cut to apredetermined length based on the standard of the drum. In order tomanufacture two drums having different lengths, it is necessary todifferently adjust the interval between the front lifters 61 a, 62 a,and 63 a and the rear lifters 61 b, 62 b, and 63 b in accordance withthe length of the drum.

For example, as illustrated in FIGS. 5A and 5B, the interval between thefront lifters 61 a, 62 a, and 63 a and the rear lifters 61 b, 62 b, and63 b when the length of the drum 51′ is long (see FIG. 5A) needs to begreater than the interval between the front lifters 61 a, 62 a, and 63 aand the rear lifters 61 b, 62 b, and 63 b when the length of the drum51″ is short (see FIG. 5B), so that the laundry may be uniformly liftedup by the front and rear lifters 61 b, 62 b, and 63 b even in the caseof the large-capacity drum 51.

Therefore, extra mounting slots 511 a are further formed in the drum 51in order to adjust the installation position of at least one of thefront lifters 61 a, 62 a, and 63 a or the rear lifters 61 b, 62 b, and63 b in the front-rear direction when the length of the drum is changed.

In the present exemplary embodiment, the extra mounting slots 511 a areprovided to adjust the installation positions of the front lifters 51 a,52 a, and 53 a, but the present disclosure is not necessarily limitedthereto. Depending on exemplary embodiments, the extra mounting slots511 b may be provided to adjust the installation positions of the rearlifters 61 b, 62 b, and 63 b.

The extra mounting slots 511 a may be formed in the lifter frame 620such that the extra mounting slots 511 a correspond in number to themounting slots 511 a (hereinafter, referred to as ‘installation slots’)into which the insertion protrusions 627 are inserted, and the extramounting slots 511 a may be formed at points spaced apart from therespective installation slots at a predetermined distance D in thefrontward or rearward direction. The installation position of the lifterframe 620 may be changed by the distance D by separating the insertionprotrusion 627 from the mounting slot (for example, 511 a 1) and theninserting the insertion protrusion 627 into the extra mounting slot (forexample, 511 a 2).

Meanwhile, in the exemplary embodiment, the extra opening portions 512 aare provided to adjust the installation positions of the front lifters51 a, 52 a, and 53 a, but the present disclosure is not necessarilylimited thereto. Depending on the embodiment, the extra opening portions512 b may also be provided to adjust the installation positions of therear lifters 61 b, 62 b, and 63 b.

Meanwhile, in the exemplary embodiment, the extra fastening holes 513 aare provided to adjust the installation positions of the front lifters51 a, 52 a, and 53 a, but the present disclosure is not limited thereto.Depending on the embodiment, the extra fastening holes 513 b may also beprovided to adjust the installation positions of the rear lifters 61 b,62 b, and 63 b.

In this regard, a planar shape of the frame cover 640 may be formed tocover a region extending from the region in which any one of themounting slots 511 a in the first group G1 and the second group G2 isformed by a spacing distance D between the mounting slots 511 a 1(1) to511 a 1(4) in the first group and the mounting slots 511 a 2(1) to 511 a2(4) in the second group.

Therefore, the installation positions of the lifters 61 a, 61 b, 62 a,62 b, 63 a, and 63 b may be changed depending on the type of drum 51,and the extra mounting slots for changing the installation positions maybe covered by the frame cover 640.

Meanwhile, FIGS. 20A and 20B illustrate another exemplary embodiment ofthe present disclosure. In order to install the lifter frame 620 bymeans of the front mounting slot 511 a, the lifter frame 620 needs to bepushed forward after the insertion protrusion 627 is inserted into theinsertion section 51. In order to install the lifter frame 620 by meansof the rear mounting slot 511 b, the lifter frame 620 needs to be pushedrearward after the insertion protrusion 627 is inserted into theinsertion section 51.

On the contrary, in order to separate the lifter frame 620 from the drum51, the lifter frame 620 is pushed forward or rearward to move thecatching portion 627 b of the insertion protrusion 627 from the bindingsection S2 and align the catching portion 627 b with the insertionsection 51, and the lifter frame 620 is lifted up, such that thecatching portion 627 b passes through the insertion section 51, and thelifter frame 620 may be separated from the drum 51.

FIGS. 16A and 16B are views illustrating a pair of front and rearlifters illustrated in FIG. 1; FIG. 17 is a view illustrating thelifters illustrated in FIGS. 16A and 16B when viewed from a front side;FIG. 18A is a view illustrating a state in which the drum illustrated inFIG. 1 is deployed and FIG. 18B is a developed view of the drum havingthe lifters disposed according to another exemplary embodiment of thepresent disclosure; FIG. 19 is a view (a) illustrating a change inheight of a first fabric caused by the rear lifter in accordance with arotation angle of the drum and a view (b) illustrating a change inheight of a second fabric caused by the front lifter that constitutes aset together with the rear lifter; Hereinafter, description will be madewith reference to FIGS. 16A to 19.

Each of the front lifters 61 a, 62 a, and 63 a is disposed on the innercircumferential surface of the drum 51 and extending in the front-reardirection. The plurality of front lifters 61 a, 62 a, and 63 a aredisposed based on the rotation axis O at equal angles.

The rear lifters 61 b, 62 b, and 63 b are disposed on the innercircumferential surface of the drum 51 and positioned rearward from thefront lifters 61 a, 62 a, and 63 a. Like the front lifters 61 a, 62 a,and 63 a, the rear lifters 61 b, 62 b, and 63 b are disposed based onthe rotation axis O at equal angles.

The rear lifters 61 b, 62 b, and 63 b are disposed to form apredetermined phase angle with the front lifters 61 a, 62 a, and 63 awith respect to the rotation axis O. Here, the ‘phase angle’ is made bydefining, as a rotation angle of the drum 51, a point in time at whichthe lifters 61 a, 62 a, 63 a, 61 b, 62 b, and 63 c reach a point on thecircumference. Assuming that the drum 51 is rotated clockwise CW in theexemplary embodiment, the rear lifters 61 b, 62 b, and 63 b reach thesame height prior to the front lifters 61 a, 62 a, and 63 a by a degreecorresponding to the phase angle Δθ.

As illustrated in FIGS. 16A to 17, assuming that each of the lifters 61a, 62 a, 63 a, 61 b, 62 b, and 63 b has a length C1 extending in thefront-rear direction and a width C2 defined in the left-right direction(or a direction orthogonal to the longitudinal direction), acircumferential distance (C3=Δθr, see FIG. 19) corresponding to thephase angle is larger than 0 and equal to or smaller than two times thewidth C2 in the circumferential direction of each of the front lifters61 a, 62 a, and 63 a.

Referring to FIGS. 18A and 18B, a no-lifter region SE, in which there isno front lifter or rear lifter, is formed between any one pair offront/rear lifters (for example, 61 a and 61 b) and another pair offront/rear lifters (for example, 62 a and 62 b) on the innercircumferential surface of the drum 51. The no-lifter region SE mayextend from the front end to the rear end of the drum 51.

Specifically, the no-lifter region SE passes between the two adjacentsets of lifters from the front end of the drum 51 and extends to therear end of the drum 51. Specifically, the no-lifter region SE extendsstraight from the front end of the drum 51 to the rear end of the drumwhile passing between the two adjacent front lifters (for example, 61 aand 62 a) among the plurality of front lifters 61 a, 62 a, and 63 a andbetween the two rear lifters 61 b and 62 b that each form the phaseangle Δθ with each of the two adjacent front lifters 61 a and 62 a.

Since the no-lifter region SE extends straight from the front end to therear end of the drum 51, the laundry may be uniformly distributed to thefront and rear regions of the drum 51 in the no-lifter region SE.

Typically, the washing machine detects eccentricity of the drum 51before performing a spin-drying process, and when the detectedeccentricity is within a reference value, the drum is accelerated suchthat the rotational speed of the drum 51 reaches a predeterminedspin-drying speed (or spin-drying RPM). Otherwise, a fabric distributionis performed to change the position of fabrics in the drum 51. Thefabric distribution is repeated if the detected eccentricity does notreach the reference value. When the number of times the fabricdistribution is repeated reaches a predetermined number of times, it isdetermined that the fabric distribution has failed, and the spin-dryingis stopped.

In the washing machine according to the present exemplary embodiment, afirst fabric positioned at the rear side of the drum 51 (that is, thefabric to be lifted up by the rear lifters 61 b, 62 b, and 63 b) and asecond fabric positioned at the front side of the drum 51 (that is, thefabric to be lifted up by the front lifters) flow with a time difference(or a phase difference) by the phase angle Δθ formed by the frontlifters 61 a, 62 a, and 63 a and the rear lifters 61 b, 62 b, and 63 b,and as a result, the fabric distribution may be more smoothly performed.

More specifically, referring to FIG. 19, when the drum 51 is rotatedclockwise CW in a state in which the rear lifters 61 b, 62 b, and 63 bare positioned at a lowest point (θ=0) of the drum 51, the first fabricbegins to be lifted up first by the rear lifters 61 b, 62 b, and 63 b,and then the second fabric begins to be lifted up by the front lifters61 a, 62 a, and 63 a after the time corresponding to the phase angle Δθhas passed.

Assuming that the fabrics roll (θ<π/2) and that a position P at whichthe fabric lifted up by the lifters 61 a, 62 a, 63 a, 61 b, 62 b, and 63b falls is a position Pd, the first fabric lifted up by the rear lifters61 b, 62 b, and 63 b reaches the position (or height) Pd and fallsfirst, and then the second fabric lifted up by the front lifters 61 a,62 a, and 63 a reaches the position Pd and falls.

The first fabric and the second fabric move with a time differencewithout forming lumps, and thus may be evenly distributed. As a result,it is possible to reduce the number of times the fabric distribution isrepeated, reduce the instances of failure to enter the spin-dryingstage, and reduce the overall washing time including the spin-dryingtime.

In addition, since the fabrics flow with a phase difference when thefabrics roll or tumble, friction or collision between the fabrics causedby the relative movement occurs more frequently, such that contaminationmay be more effectively removed by the washing operation (that is,washing power is improved).

Meanwhile, FIGS. 20A and 20B are views illustrating a modified examplein which the lifters are disposed, in which FIG. 20A illustrates asmall-capacity drum and FIG. 20B illustrates a large-capacity drum.Referring to FIGS. 20A and 20B, one set of front lifters 61 a, 62 a, and63 a and rear lifters 61 b, 62 b, and 63 b may be disposed in a row inthe front-rear direction. That is, the front lifters 61 a, 62 a, and 63a and the rear lifters 61 b, 62 b, and 63 b, which constitute one set,may be arranged on the same line without being spaced apart from oneanother in the circumferential direction.

FIG. 21 is a view illustrating another exemplary embodiment of thelifter. The exemplary embodiment illustrated in FIG. 21 provides alifter 64 including a lifter frame 620′ and a frame cover 640′ slightlydifferent in shape from those in the above-mentioned exemplaryembodiments, but similar in detailed configuration to those in theabove-mentioned exemplary embodiments. Therefore, constituent elementsidentical to the constituent elements according to the above-describedexemplary embodiments will be assigned the same reference numerals, anda specific description thereof will be omitted.

While the invention has been explained in relation to its embodiments,it is to be understood that various modifications thereof will becomeapparent to those skilled in the art upon reading the specification.Therefore, it is to be understood that the invention disclosed herein isintended to cover such modifications as fall within the scope of theappended claims.

What is claimed is:
 1. A laundry treating apparatus comprising: a drumconfigured to rotate about a rotation axis that extends in a front-reardirection of the laundry treating apparatus, the drum defining anopening at a circumferential surface of the drum and comprising acatching tab that extends from a side of the opening; and a lifterdisposed on an inner circumferential surface of the drum and configuredto rotate about the rotation axis based on rotation of the drum, thelifter comprising: a lifter frame coupled to the inner circumferentialsurface of the drum, and a frame cover that is coupled to the lifterframe and that protrudes radially inward from the inner circumferentialsurface of the drum, wherein the lifter frame comprises: a frame basethat is coupled to the inner circumferential surface of the drum andthat defines a seating groove that extends along a circumference of theframe base, a frame upper plate spaced apart from the frame base in adirection toward an inside of the drum, a frame sidewall that connectsthe frame upper plate and the frame base to each other, and a catchingprotrusion that protrudes from an inner surface of the lifter frame andthat is configured to contact the catching tab of the drum based on thelifter frame coupling to the inner circumferential surface of the drum,and wherein the catching protrusion has a symmetrical shape with respectto one or more axes passing a center of the lifter frame.
 2. The laundrytreating apparatus of claim 1, wherein the catching protrusion defines afirst concave portion and a second concave portion that are symmetricalto each other with respect to each of the one or more axes of the lifterframe.
 3. The laundry treating apparatus of claim 2, wherein thecatching protrusion is disposed at the center of the lifter frame. 4.The laundry treating apparatus of claim 1, wherein the frame covercomprises: a cover upper plate having an inner surface that faces theframe upper plate; and a cover sidewall that extends from the coverupper plate toward the frame base, the cover sidewall having a lower endinserted into the seating groove and an upper end connected to the coverupper plate.
 5. The laundry treating apparatus of claim 4, wherein theframe cover has a symmetrical shape with respect to the one or more axespassing the center of the lifter frame.
 6. The laundry treatingapparatus of claim 1, wherein the lifter frame further comprises aninsertion protrusion comprising: a vertical portion that extendsdownward from a bottom surface of the frame base; and a catching portionthat is bent from a lower end of the vertical portion toward an insideof the frame base.
 7. The laundry treating apparatus of claim 6, whereinthe insertion protrusion comprises a plurality of insertion protrusionsthat are arranged symmetrically with respect to the one or more axespassing the center of the lifter frame.
 8. The laundry treatingapparatus of claim 7, wherein the drum further comprises: a first groupof mounting slots defined in a first area of the drum; and a secondgroup of mounting slots defined in a second area of the drum spacedapart from the first area in a rearward direction of the drum, whereinat least a portion of the first group of mounting slots overlap with atleast a portion of the second group of mounting slots in acircumferential direction of the drum, wherein each of the plurality ofinsertion protrusions is configured to selectively insert into one ofthe first group of mounting slots or the second group of mounting slots,wherein the drum defines a pair of openings in the inner circumferentialsurface of the drum that are spaced apart from each other in thefront-rear direction, and wherein a distance between the pair ofopenings is equal to a distance between one of the first group ofmounting slots and one of the second group of mounting slots.
 9. Thelaundry treating apparatus of claim 8, wherein the frame cover comprisesa planar portion that covers a region of the drum between the first areaand the second area, the planar portion having a length corresponding tothe distance between the one of the first group of mounting slots andthe one of the second group of mounting slots.
 10. The laundry treatingapparatus of claim 7, wherein the frame cover comprises a coupling tabthat protrudes from a lower end of the frame cover, and wherein thelifter frame comprises a tab binding port defined in the seating grooveand configured to receive the coupling tab based on the lifter framecoupling to the frame cover.
 11. The laundry treating apparatus of claim10, wherein the seating groove defines a closed curve that extends alongthe circumference of the frame base, and wherein a horizontal projectionof each of the plurality of insertion protrusions is positioned withinin the closed curve.
 12. The laundry treating apparatus of claim 1,wherein the lifter frame further comprises a fastening boss thatprotrudes from an inner surface of the lift frame toward the innercircumferential surface of the drum, and wherein the drum defines afastening hole configured to receive a fastening member through thefastening boss to thereby couple the lifter to the drum.
 13. The laundrytreating apparatus of claim 12, wherein the fastening boss protrudesfrom an inner surface of the frame upper plate toward the innercircumferential surface of the drum.
 14. The laundry treating apparatusof claim 1, wherein the lifter frame is made of synthetic resin, and theframe cover is made of metal.
 15. The laundry treating apparatus ofclaim 1, wherein the lifter comprises: a plurality of front liftersarranged in a circumferential direction of the drum; and a plurality ofrear lifters arranged in the circumferential direction of the drum anddisposed rearward relative to the plurality of front lifters.
 16. Alaundry treating apparatus comprising: a tub configured to receivewashing water; a drum configured to receive laundry and configured torotate in the tub about a rotation axis that extends in a front-reardirection of the laundry treating apparatus; and a lifter disposed on aninner circumferential surface of the drum and configured to rotate aboutthe rotation axis based on rotation of the drum, wherein the liftercomprises: a lifter frame installed on the inner circumferential surfaceof the drum, and a frame cover that is coupled to the lifter frame andthat protrudes radially inward from the inner circumferential surface ofthe drum, and wherein the lifter frame comprises a catching protrusionthat protrudes from an inner surface of the lifter frame and that has asymmetrical shape with respect to one or more axes passing through acenter of the lifter frame.
 17. The laundry treating apparatus of claim16, wherein the catching protrusion defines a first concave portion anda second concave portion that are symmetrical to each other with respectto each of the one or more axes of the lifter frame.
 18. The laundrytreating apparatus of claim 17, wherein the drum comprises: a firstgroup of mounting slots defined in a first area of the drum; and asecond group of mounting slots defined in a second area spaced apartfrom the first area in a rearward direction, wherein at least a portionof the first group of mounting slots overlap with at least a portion ofthe second group of mounting slots in a circumferential direction of thedrum, and wherein the frame cover comprises a planar portion that coversa region of the drum between the first area and the second area, theplanar portion having a length corresponding to a distance between oneof the first group of mounting slots and one of the second group ofmounting slots.
 19. The laundry treating apparatus of claim 16, whereinthe lifter frame further comprises: an insertion protrusion comprising avertical portion that extends downward from a bottom surface of thelifter frame and a catching portion that is bent from a lower end of thevertical portion toward an inside of the lifter frame, wherein thelifter frame defines a seating groove that extends along a circumferenceof the lifter frame and that receives a lower end of the frame cover,and wherein the seating groove defines a closed curve, and a horizontalprojection of the insertion protrusion is positioned within in theclosed curve.
 20. The laundry treating apparatus of claim 16, whereinthe lifter frame further comprises a fastening boss that protrudes froman upper inner surface of the lifter frame toward the innercircumferential surface of the drum, and wherein the drum defines afastening hole configured to receive a fastening member through thefastening boss to thereby couple the lifter to the drum.